How to reverse a series of variable assignments?

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In my code, I frequently have blocks of code of the form
var1 = setting1;
othervar2 = othersetting2;
somevar3 = somesetting3;
where I don't have names of the variables or settings in some way that i can program. Even if i did, I think i would be using eval, and i don't want to do that.
It's common that i later wish to perform analogus assignments in reverse, so i would have a block like
setting1 = var1;
othersetting2 = othervar2;
somesetting3 = somevar3;
This can be very tedious to write out. Does there exist a standard way to performing a line-by-line edit which swaps the left and right side of the variable assignment?
I imagine If i copy the code into a text file, it wouldn't be too hard to write a script that produces a new text file with all the variable assignments swapped, but I wonder if this exists already or if there's a term for this.

Accepted Answer

Michael Van de Graaff
Michael Van de Graaff on 11 Mar 2021
I did find a quick solution. On the File Exchange Alessandro Masullo has a function which aligns a block of variable assignments by their equal signs. https://www.mathworks.com/matlabcentral/fileexchange/47918-align-equal-sign
I modified the code to simply place the pre-equal sign part where the post-equal sign part was and vice-versa. my modification is explained in the comments on his alignEquals upload. then running the unmodified alignEquals makes things looks good again.

More Answers (1)

Rik
Rik on 11 Mar 2021
Edited: Rik on 11 Mar 2021
I tend to use deal to make it more or less compact:
[var,othervar,somevar]=deal(setting1,othersetting,somesetting);
Now if I want to reverse this I only need to swap the parts between the braces and parentheses, which is easy and fast.
However, you could do some magic with eval (and inputname to make it somewhat robust). The result will not be very clean. You might also consider something like the function below.
function varargout=flipflop_assign(order,varargin)
varargout=varargin(order);
end
  6 Comments
Rik
Rik on 2 Apr 2021
That might be the case. I never use AppDesigner, but I always create GUIs in the normal editor (and I would do so for a class-based GUI as well).

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